Occlusal Assessment of Zirconia Crowns Designed with the Digital Articulator and Traditional Methods

Purpose To evaluate and compare the occlusal fit of zirconia crowns designed using a digital articulator method and the traditional method in a self-controlled clinical trial. Materials and methods Two zirconia crowns each were prepared for 12 patients with a single posterior tooth defect using two different methods: a digital articulator method and the traditional method. In the traditional method, casts were scanned using a model scanner, and the relative positions of the maxillary and mandibular arches were determined by the intercuspal occlusion of the casts. In the digital articulator method, casts were mounted on a mechanical articulator and scanned, and the relative positions were determined by their respective positions in the articulator. Additional dynamic occlusal adjustments of the digital articulator crowns were performed. Both groups of zirconia crowns were milled in a five-axis milling machine. The time required for occlusal adjustments, the occlusal contacts, the occlusal contact distributions, the number of occlusal contacts, the relative occlusal forces, and patient satisfaction (visual analog scale score) were evaluated. Wilcoxon test, McNemar test, and paired t test were used to compare the parameters between the two methods. Results The occlusal adjustment times for the digital articulator and traditional method crowns were 327 ± 226 seconds and 395 ± 338 seconds, respectively (P > .05). There were no significant differences in occlusal contacts, occlusal contact distributions, number of occlusal contacts, relative occlusal forces, or VAS scores between the two methods (P > .05). Conclusion A digital articulator method for single-crown restoration was applied successfully. Crowns fabricated using a digital articulator or the traditional method can achieve acceptable occlusal fit for single-crown restorations.